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R Kaiser

Publications and source records attributed to R Kaiser.

At least 145 records · Page 8Linked to original sources
PubMed1995

[Intrathecal IgG synthesis: when is determination of oligoclonal bands necessary?].

Two quantitative methods of determining the intrathecal synthesis of IgG were tested for their usefulness in deciding about the necessity of further investigations of oligoclonal bands (OCB) in the CSF. For this purpose, in 2003 patients with various neurological diseases the intrathecal synthesis of IgG was determined by Reiber's formula and by the IgG index, as well as by the demonstration of OCB by isoelectric focusing (IEF). While OCB could be detected in no patient with an IgG index < 0.45, these bands were always demonstrated in patients with an index > 0.80. Even though arrange of 0.45-0.8 OCB was only detected in 268/1316 patients (20.4%), in 190/268 samples (70.8%) OCB were the only criterion for intrathecal synthesis of IgG. Calculation of intrathecal synthesis of IgG by Reiber's formula was less helpful in deciding about the necessity for IEF. Even though they had no intrathecal synthesis of IgG, as calculated by Reiber's formula, 189/1472 patients (12.8%) had OCB in the CSF. OCB were always detected if local production of IgG was > 12%. In patients with a severe damage of the blood-CSF barrier, calculation of the IgG index gave more false-positive results than calculations using Reiber's formula.

Adult↗
PubMed1994

Identification of the phosphorylation site for cAMP-dependent protein kinase on Na+,K(+)-ATPase and effects of site-directed mutagenesis.

Phosphorylation of purified Na+,K(+)-ATPase by cAMP-dependent protein kinase (protein kinase A) decreases the activity of this enzyme. We have now shown, using several experimental approaches, that a highly conserved seryl residue on the catalytic (alpha) subunit of Na+,K(+)-ATPase, corresponding to Ser943 of the rat alpha 1 isoform, is the phosphorylation site for protein kinase A. cDNAs corresponding to wild-type Na+,K(+)-ATPase and Na+,K(+)-ATPase in which Ser943 was mutated to Ala were transfected into COS cells. Treatment of the transfected cells with forskolin plus 3-isobutyl-1-methylxanthine resulted in a decrease in the activity of the wild-type enzyme but not in that of the mutated enzyme. The results suggest that, in intact cells, the activity of the Na+,K(+)-ATPase is regulated in part by signal transduction pathways that use protein kinase A-dependent phosphorylation of the Na+,K(+)-ATPase alpha subunit.

1-Methyl-3-isobutylxanthine↗
PubMed1994

Monomeric and dimeric forms of cholesterol esterase from Candida cylindracea. Primary structure, identity in peptide patterns, and additional microheterogeneity.

Cholesterol esterase from Candida cylindracea was separated into two fractions, corresponding to a dimeric and a monomeric form. Fingerprint analysis after lysine cleavages shows identical patterns, suggesting lack of primary differences. Crystals obtained from the two proteins differ and suggest the possibility of an equilibrium between the two forms, influenced by the substrate cholesterol linoleate, which appears to stabilize the more active, dimeric form. All crystals have dimers as the asymmetric unit. The primary structure of the enzyme was determined at the peptide level and shows only one difference, Leu-350 instead of Ile, from a DNA-deduced amino acid sequence, and conservation of features typical for cholesterol esterases characterized.

Amino Acid Sequence↗
PubMed1994

Purification, characterization, and high performance liquid chromatography assay of Salmonella glucose-1-phosphate cytidylyltransferase from the cloned rfbF gene.

We report the purification and characterization of glucose-1-phosphate cytidylyltransferase, the first of five enzymes committed to biosynthesis of CDP-D-abequose from Salmonella enterica strain LT2. The purification was greatly facilitated by using a cloned rfbF gene encoding this enzyme. Pure enzyme was obtained by 64-fold enrichment in three chromatography steps. The NH2-terminal sequence of the purified enzyme was in agreement with the sequence predicted from the nucleotide sequence of the rfbF gene. The SDS-polyacrylamide gel electrophoresis estimated subunit M(r) of 31,000 agrees well with the M(r) of 29,035 calculated from the amino acid composition deduced from the nucleotide sequence of the rfbF gene. The glucose-1-phosphate cytidylyltransferase catalyzes a reversible bimolecular group transfer reaction and steady-state kinetic measurements, including product inhibition patterns, indicate that this reaction proceeds by a "ping-pong" type of mechanism. The Km values for CTP, alpha-D-glucose 1-phosphate, CDP-D-glucose, and pyrophosphate are 0.28, 0.64, 0.11, and 1.89 mM, respectively.

Amino Acid Sequence↗
PubMed1994

Variable CSF findings in early and late Lyme neuroborreliosis: a follow-up study in 47 patients.

The cerebrospinal fluid (CSF) of 37 patients with early Lyme neuroborreliosis (ELN) and of 10 patients with late Lyme neuroborreliosis (LLN, duration of symptoms > or = 7 months) was investigated for typical features differentiating between acute and chronic courses of disease. Individual patients were studied after 2 and 4 weeks, and 3, 6, and 12 months. Patients with ELN presented predominantly with symptoms of the peripheral nervous system, while patients with LLN generally suffered from symptoms of the central nervous system. At the first lumbar puncture, patients with ELN revealed a more intense pleocytosis in the CSF (P < 0.02) and a higher intrathecal synthesis of total IgM (P < 0.0003) and of Borrelia burgdorferi-specific IgM antibodies (P < 0.01). At the same time, in patients with LLN, the blood-CSF barrier was more severely impaired (P = 0.03), and local production of total IgG (P = 0.0001), of B. burgdorferi-specific IgG antibodies (P = 0.03) and of total IgA (P = 0.001) was more markedly increased. The quantity of intrathecally produced B. burgdorferi-specific IgA antibodies did not differ between the two study groups. Clinical recovery was usually accompanied by a considerable improvement of the blood-CSF barrier function and pleocytosis. After 6 months, the intrathecal synthesis of total IgG had significantly decreased in patients with ELN but not in those with LLN. At the same time, the CSF of most patients in both study groups still contained intrathecally produced B. burgdorferi-specific IgG antibodies. In the absence of clinical illness or symptoms of inflammation 6 and 12 months after treatment, B. burgdorferi-specific IgG antibodies in the CSF might simply indicate an anamnestic reaction to a previous infection of the central nervous system. Six months after antibiotic treatment, patients with ELN still revealed evidence of intrathecal synthesis of total IgM, whereas those with LLN did not. These antibodies, however, were not related to B. burgdorferi.

Adult↗
PubMed1994

Parallel evolution in the V3 region of HIV type 1 after infection of hemophiliacs from a homogeneous source.

To determine the genetic diversification in the highly functional V3 loop, we followed up five hemophiliacs who were infected by a homogeneous HIV-1 population from a contaminated clotting factor lot. Initially, all patients displayed identical DNA sequences in this part of the proviral env gene. Therefore, this unique outbreak allows us to investigate the biological and genetic development of a common ancestor virus in different patients. A high degree of homology is maintained in the predominant sequences from 5 until 35 months after seroconversion. Only one patient showed a remarkable diversification 3 years postinfection. However, these genetic changes in the V3 region were not associated with disease progression. Discontinuous sequence changes were observed mainly in a region downstream of the V3 loop. Two positions in particular are involved in a sequence evolution within the V3 loop leading to the same amino acids in different patients. These directed changes occurred at sites that are reported to be critical for the specificity of antibodies (position 308) and viral cytopathicity (position 324). However, the parallel evolution was associated neither with differentiation of the viral phenotype nor with progression of the disease.

Amino Acid Sequence↗
PubMed1994

Prospective evaluation of epidural versus intrapleural catheters for analgesia in chest wall trauma.

Severe blunt chest trauma can produce multiple rib fractures, flail segments, and pulmonary contusions. All of these injuries produce pain and diminished pulmonary function. The effectiveness of intrapleural and epidural administration of bupivacaine was prospectively evaluated in 19 patients with severe chest trauma. Pain relief and pulmonary function were evaluated for 72 hours after catheter placement. Epidural administration of bupivacaine significantly reduced pain at rest and with motion compared with the intrapleural route (p < 0.05). Parenteral narcotic use was also significantly less in the epidural group (p < 0.05). Negative inspiratory pressure and tidal volume were significantly increased with epidural anesthesia (p < 0.05). Vital capacity, FIO2, minute ventilation, and respiratory rate were not affected. Mild hypotension was a common complication with epidural catheters. We conclude that continuous epidural analgesia is superior to intrapleural block and significantly improves tidal volume and negative inspiratory pressure.

Adult↗
PubMed1994

Serological and virological markers of human parvovirus B19 infection in sera of hemophiliacs.

It is known that parvovirus B19 (B19) is transmitted to hemophiliacs by clotting factors prepared from human plasma. However, it is not clear whether B19 is also transmitted by the more recently used inactivated clotting factor preparations. Therefore, we investigated 69 hemophiliacs, mostly children, receiving only virus-inactivated clotting factors. 49 of them (71%) were B19 IgG-positive and 18 of the IgG-positive hemophiliacs (37%) were also B19 IgM-positive. In contrast, out of 73 age-matched controls only 10 (14%) were IgG-positive, two of them being also IgM-positive. In hemophiliacs treated before 1984 with non-inactivated clotting factors, seroprevalence was very similar: 94/136 (69%) presented B19 IgG antibodies as compared to their age-matched controls with 16/50 (32%). Out of the 94 IgG-positive patients 24 (26%) were IgM-positive, whereas IgM antibodies were never found in 16 sera of 16 IgG-positive controls. In 4 out of 24 IgM positive hemophiliacs, B19 DNA was detected in the sera by using the polymerase chain reaction. However, B19 DNA was also found in 3/69 anti-B19 IgM-negative, HIV-infected hemophiliacs (all three patients in CDC stage IV). Since it seems unlikely that the results only represent passive acquisition of B19 DNA from blood products and induction of antibodies by immunization with inactivated antigen, the observations rather suggest that infection with B19 is transmitted by clotting factors, including those treated for virus inactivation.

Acute Disease↗
PubMed1993

Origin of the human alcohol dehydrogenase system: implications from the structure and properties of the octopus protein.

In contrast to the multiplicity of alcohol dehydrogenase in vertebrates, a class III type of the enzyme [i.e., a glutathione-dependent formaldehyde dehydrogenase; formaldehyde; NAD+ oxidoreductase (glutathione-formylating), EC 1.2.1.1.] is the only form detectable in appreciable yield in octopus. It is enzymatically and structurally highly similar to the human class III enzyme, with limited overall residue differences (26%) and only a few conservative residue exchanges at the substrate and coenzyme pockets, reflecting "constant" characteristics of this class over wide time periods. It is distinct from the ethanol-active "variable" class I type of the enzyme (i.e., classical liver alcohol dehydrogenase; alcohol:NAD+ oxidoreductase, EC 1.1.1.1). The residue conservation of class III is also spaced differently from that of class I but is typical of that of proteins in general, emphasizing that class I, with divergence at three functional segments, is the form with deviating properties. In spite of the conservation in class III, surface charges differ considerably. The apparent absence of a class I enzyme in octopus and the constant nature of the class III enzyme support the concept of a duplicative origin of the class I line from the ancient class III form. Still more distant relationships define further enzyme lines that have subunits with other properties.

Alcohol Dehydrogenase↗
PubMed1993

Cephalopod alcohol dehydrogenase: purification and enzymatic characterization.

Octopus, squid and cuttle-fish organs were examined for alcohol dehydrogenase activity. Only one form was detectable, with properties typical of mammalian class III alcohol dehydrogenase. The corresponding protein was purified from octopus and enzymatically characterized. Ion-exchange and affinity chromatography produced a pure protein in excellent yield (73%) after 1600-fold purification. Enzymatic parameters with several substrates were similar to those for the human class III alcohol dehydrogenase, demonstrating a largely conserved function of the enzyme through wide lines of divergence covering vertebrates, cephalopods and bacteria. The results establish the universal occurrence of class III alcohol dehydrogenase and its strictly conserved functional properties in separate living forms. The absence of other alcohol dehydrogenases in cephalopods is compatible with the emergence of the ethanol-active class I type at a later stage, in lineages leading to vertebrates.

Alcohol Dehydrogenase↗
PubMed1993

Intrathecal synthesis of IgM and IgA in neurological diseases: comparison of two formulae with isoelectric focusing.

The intrathecal IgM and IgA immune response was studied by detecting oligoclonal IgM and IgA bands in CSF and by determining both the IgM/IgA indices as well as the intrathecal production of IgM and IgA by the Reiber formula. A good correlation was found between the demonstration of oligoclonal IgM (r = 0.890) and IgA bands (r = 0.927) and the Reiber formula. Compared with the finding of oligoclonal IgM/IgA bands calculation of an intrathecal IgM/IgA synthesis by the Reiber formula was less sensitive (86%). In two out of 22 controls and in 12 of 19 patients with polyradiculitis IgM and IgA indices were elevated while the other evaluation methods were negative. Even though oligoclonal IgM and IgA bands are considered to be a useful diagnostic tool in detecting intrathecal synthesis of IgM and IgA, i.e. in meningoencephalitis or neuroborreliosis for clinical practice, the Reiber formula provides reliable results. Detection sensitivity of assays for CSF-IgM and -IgA should be at least 1.0 mg/l.

Adolescent↗
PubMed1993

Purification, characterization and HPLC assay of Salmonella glucose-1-phosphate thymidylyl-transferase from the cloned rfbA gene.

We here report on the purification and characterization of glucose-1-phosphate thymidylyl-transferase, the first of four enzymes committed to biosynthesis of dTDP-L-rhamnose from Salmonella enterica strain LT2. The purification was greatly facilitated by the cloning of the rfbA gene encoding this enzyme. Pure enzyme was obtained by 109-fold enrichment in three chromatography steps. The glucose-1-phosphate thymidylytransferase catalyzes a reversible bimolecular group transfer reaction and kinetic measurements indicate that it acts by a 'ping-pong' mechanism. The Km values for dTTP and alpha -D-glucose 1-phosphate in the forward reaction are 0.020 mM and 0.11 mM, respectively. In the reverse reaction the Km values for dTDP-D-glucose and diphosphate are 0.083 mM and 0.15 mM, respectively. The enzyme also accepts UTP and UDP-D-glucose and alpha-D-glucosamine 1-phosphate is accepted equally as well as alpha-D-glucose 1-phosphate. The NH2-terminal sequence of glucose-1-phosphate thymidylyl-transferase agrees with the sequence predicted from the nucleotide sequence of the orf6.1 gene of the rfb gene cluster. The SDS/PAGE estimated subunit mass of 31 kDa agrees well with that calculated from the amino acid composition deduced from the nucleotide sequence of the orf6.1 gene (32453 Da).

Amino Acid Sequence↗
PubMed1993

Guillain-Barré syndrome following streptokinase therapy.

Clinical and laboratory data from a patient with Guillain-Barré syndrome indicated a probable etiological correlation of polyradiculitis to the intravenous administration of streptokinase. Oligoclonal IgG bands in the cerebrospinal fluid and serum were shown to be specific for streptokinase. Serum titers of streptokinase were elevated 64-fold for IgG, 16-fold for IgM, and 4-fold for IgA compared to controls. Clinical symptoms of Guillain-Barré syndrome are thought to result from streptokinase antibody complex mediated damage to the local blood-nerve barrier. The pathogenic relevance of autoantibodies to albumin and proteins of the central and peripheral nervous systems, occurring early after onset of symptoms, remains to be determined.

Autoantibodies↗
PubMed1993

Intrathecal synthesis of specific antibodies in neuroborreliosis. Comparison of different ELISA techniques and calculation methods.

The sensitivity of six different ELISA techniques and calculation methods for the determination of intrathecal synthesis of IgG antibodies specific to Borrelia burgdorferi was investigated in paired CSF and serum specimens from 33 patients with neuroborreliosis. The diagnostic value of the Antibody Index (AI) was compared with the meaningfulness of serum antibodies to B. burgdorferi (Bb), established by immunofluorescence assay (IFA). The AI, as a standard for intrathecal antibody synthesis was determined from specific antibody ratios (QBb) in the CSF and serum and the CSF/serum ratio of IgG (QIgG) or albumin (QAlb). Using Western blotting with identical concentrations of IgG in the CSF and serum all patients displayed intrathecal synthesis of specific antibodies to at least two B. burgdorferi proteins. The different ELISA methods and calculation procedures were almost equivalent in demonstrating intrathecal synthesis of specific antibodies (32 and 33/33). Calculation of AI from IFA titers was somewhat less sensitive (30/33). In 5 patients titers of serum IgG- and IgM-antibodies to B. burgdorferi determined by IFA were within the normal range or borderline, while elevated AIBb values indicated an autochthonous immune response to B. burgdorferi in the CSF. In uncertain cases of neuroborreliosis calculation of AI from ELISA titers will be useful in clarifying the diagnosis.

Antibodies, Bacterial↗
PubMed1993

[Gestagen-estrogen combinations in gynecology. On the history, dosage and use of a hormone principle].

The first experimental and clinical investigations with gestagen-oestrogen combinations were undertaken in the late 'forties and the early' fifties of this century. In the course of further research and development, the dosage and mixture ratio of this hormonal principle were adjusted, according to the physiological status of the corpus luteum phase and its imitation by means of administration of hormonal doses. Considering the relatively large individual variations, an average daily production of 0.05 mg oestradiol/oestrone and 25 mg progesterone can be assumed, the mixture ratio being 1:50. Further indicators for the dosage were obtained by studying the biological valency of the semi-synthetic substances on the basis of the following parameters: transformation dose, menstruation delay test, anti-oestrogenic effectiveness and ovulation inhibition dose. Finally, dosage was also determined by the relevant indications; in this respect, depending on the intended use, preparations with the emphasis either on the oestrogen component or the gestagen component were deliberately produced. Up to the end of the 'fifties', parenteral gestagen-oestrogen combinations were the only preparations available for gynaecological hormonal therapy. Oral medication was predominant from 1957 onwards. The high ranking achieved by the combination preparations was due to their properties with respect to regulating menstrual haemorrhage and inhibiting proliferation and ovulation, as well as to their antiandrogenic properties. As far as methods of application were concerned, cyclical administration was most frequently employed (including phase variants), therapeutic amenorrhoea being second, whereas high-dosage application in the sense of hormonal pseudopregnancy was less often used. The gestagen-oestrogen combinations have become the most important hormonal principle in gynaecology as therapeutic agents and hormonal contraceptives.

Contraceptives, Oral, Combined↗